This is going to be a little long winded. About 1 & 1/2 months ago my wife hit a huge pot hole & bent the pass side wheels. I had aftermarket wheels from my other car that met the 5 X 4.25(108)bolt pattern w/ 43mm offset. After changing out the wheels & tires for the new wheels & tires there was a bad vibration. The tire shop noticed that I needed centric spacers for the wheels. I got these had them installed & not the vibration is much less, but still occurs on occation while driving at hwy speeds. It is probably doing it at slower speeds, but is not as noticable. Anyone know why this is happening? Do I need to get Volvo specific wheels?